After the urban riots of 1967 we were trained in riot control. It in was a National Guard unit based in Middleborough that would be called to active duty in March 1968. (Three weeks before the call-up, members living in Duxbury and points north were transferred to a unit in Hull. One of those bureaucratic things.)

The National Guard then was nowhere nearly as professional, nor as regularly put into harm’s way, as it is today. But riot control was taken seriously and the instructions were explicit: If theuse of a firearm is necessary, aim below the belt to stop a man; above the belt to kill him. A gunshot wound below the waist is no favor. But it might let a man live.

Today, when lethal force is deemed necessary, the officer is instructed to aim for the center of the visible target. A seemingly small distinction that erases any difference between “stopping” and “killing.” It seems obvious that in a charged confrontation this can encourage deadlier force, and more multiple rounds being fired. The targets may be reckless kids or disturbed people representing less than a deadly threat to law enforcement.

America is not now in a good place in this regard. “Black lives matter” are not words that Martin Luther King, Jr. would have used. He would and did say that all lives matter. One understands the outrage when officers of the law show disregard for black citizens’ lives. But what amounts to a war-cry does no good. Police lives also matter. If retaliatory assassinations of police officers lead to temporarily diminished police services, “activists” will move on. It is the law-abiding black working class that will pay the price for a very long time. After 48 years, neither Detroit, nor Grove Hall in Boston, has completely recovered from its 1967 riot.

The civilized reaction of the victims of the atrocity in Charleston on June 17 is almost beyond imagining. But it is consonant with what Dr. King preached after the bombing of the 16th Street Baptist Church in Birmingham on Sept. 14, 1963. Let us hope it awakens the nation to a new birth of unity.

In Duxbury in 2015, the police are well-trained in the practice of restraint. But every time any cop anywhere pulls a car over it entails a stressful encounter between two human beings. Neither can be sure how it will play out, and both know the taste of fear. We send kids to driver training, give them licenses and in many cases souped-up cars. But we do not teach them how to behave when they get pulled over — as sooner or later they will be.

So this is to kids of every age, everywhere: If those flashing lights behind you are meant for you, pull over and roll down your window. If it is nighttime turn on your interior light. The law says you must. Put your hands on top of the steering wheel where they can be seen, leave them there, and wait for instructions.

The fellow human being who has pulled you over does not know who you are or what you represent. But the officer will notice that you “know the drill,” and will appreciate it. By your cooperation you will have helped to avert a confrontation that could lead to tragedy. This is as much a verity in Duxbury as it is anywhere in the United States.